The White Sox are in the midst of a season in which the negatives have significantly outweighed the positives. In that sense, it's surprising that one of the few bright spots has flown somewhat under the radar: Jose Quintana.

Quintana burst onto the scene last year as a 23-year old, posting an impressive 3.76 ERA over 136 innings for the 2012 White Sox. Yet despite that ostensibly solid performance, there was a cloud of unease surrounding what to expect from him going forward. There were certainly legitimate reasons to have doubts. Quintana's peripherals were less than stellar in 2012, as he struck out only 5.3 batters per 9 innings and walked over half that many. His FIP was about a half run higher than his ERA, he wasn't exactly a ground ball pitcher (44.7%) and he allowed an above-average share of line drives (21.7%). During 2012, there was always a worry that opposing teams would eventually "figure him out", and his performance over the last month and a half of the 2012 season bore that out. Quintana held a 2.76 ERA on August 19th, and that rose a full run over his last 7 starts. That stretch included rough starts against the Tigers and Twins, who were seeing him for the 2nd and 3rd time, respectively. Fatigue certainly played a role, as Quintana threw 83 more innings than he did in any other professional season, but in any case, it seemed like the jig might be up.

Not so. 18 starts into his 2013 season, Quintana is looking at a 3.67 ERA. This time around, the number is much more convincing. He's striking out opposing hitters at a much more respectable rate (7.1 per 9 innings) without an increase in walk rate. A lot of that has to do with generating notably more whiffs (about 65% higher in 2013) on his fastball, partially due to an uptick in velocity. As Jim mentioned yesterday morning, Quintana is averaging about 92 mph on his fastball, a shade higher than a 1 mph increase over last year. Another piece of the puzzle is increased movement on his pitches:

Horizontal Movement (inches)

Vertical Movement (inches)

Pitch classification can sometimes be a little fuzzy, but it seems clear that Quintana is generating a little bit more horizontal movement this season. However, it's the chart of vertical movement that might be more pertinent to explaining Quintana's success, as I will explain.

The first place a critic might look to find a reason for impending regression is BABIP, and yes, Quintana's is .260, 19th-lowest in baseball among qualified pitchers. However, there's reasons for that besides just plain ol' good fortune. Quintana has allowed line drives at the 9th-lowest rate among qualified pitchers. Furthermore, he tends more towards allowing fly balls, which suppress BABIP, than grounders, which don't.

The concern, of course, is that allowing too many fly balls puts the pitcher at risk of giving up more home runs. Quintana has something of an answer for that as well. 15.3% of his fly balls allowed are infield flies, good for 3rd in baseball. Infield flies are as good for pitchers as strikeouts. Well.....almost as good. With all of this information in tow, the .260 BABIP does not look quite so fluky. This isn't so much a case of hitters slapping the ball into the defense as it is of hitters not being able to square up Quintana's pitches.

That brings us back to the discussion of pitch movement. The vertical movement on Quintana's four-seamer in 2013 puts it firmly in the "rising fastball" category (per FanGraphs, most pitchers sit in the 7-10 inches range). It may be oversimplification to solely attribute Quintana's line drive rate dropping and his infield fly rate more than doubling since 2012 to increased fastball backspin, but that certainly seems like it could be a significant contributor. In any case, the batted ball data implies hitters are swinging underneath Quintana's pitches and he's avoiding the barrel of the bat with remarkable regularity. There's some luck involved in there, but if we're looking for a partial explanation, this one fits.

So what should we expect from Jose Quintana going forward? As Tdogg mentioned in yesterday morning's thread, he's top 10 in bWAR in the AL for pitchers as of right now, which is probably setting the bar too high. However, he looks like a great bet to wind up being at least a 4-win pitcher this season when all is said and done. This is a far cry from what one looks for in a passable back-of-the-rotation starter. Based on what he's done so far, Quintana looks like he could settle in as a legitimate number three starter on a contending team. 40 starts worth of data by no means guarantees that he'll achieve that career trajectory. However, everyone's been waiting for the other shoe to drop since Quintana first overachieved his way into a starting role. Maybe it's time to revise expectations, especially with the metrics trending in the right direction.